Composition Comprising an Alkoxylated Amine Compound and a Carboxylic Acid Compound, use thereof in Water in Oil Emulsions and Process Using the Composition as or as Part of a Drilling Fluid

ABSTRACT

The object of the present invention is a composition comprising amine compound and carboxylic acid compounds, wherein at least the amine compounds are alkoxylated, use thereof as a drilling fluid, and a method for using the drilling fluid

The present invention relates to a composition containing amine andcarboxylic acid compounds as oil in water emulsifier system, the usethereof in oil based drilling fluids and a process using the drillingfluids.

RELATED ART

A drilling fluid also named drilling mud is a fluid that is pumpedthrough a drilled hole while drilling is being carried out in order toease the drilling process. The various functions of a drilling fluidinclude the removal of drilled material below the drill head,transporting the drilled material (cuttings) out of the drilled hole,cooling and lubricating the drill bit, supporting the drill pipe and thedrill bit, stabilising the drill hole walls, suspending the cuttingswhen circulation is stopped, providing a liquid column to regulate thehydrostatic pressure at the surface and preventing a “blowout”. Thecompositions of drilling fluids are often adapted to the properties of agiven geological formation in order to optimise a drilling process.Drilling fluids are usually thickened, flowable systems with a water oroil base. Oil-based drilling fluids are used for example in offshoredrilling applications and for drilling through water-sensitive layersand/or aquifers.

Oil-based drilling fluids are generally divided into invertible emulsiondrilling fluids or conventional non-invertible drilling fluids. Bothcomprise a three-phase system: a continuous oil phase, a dispersed waterphase and finely particulate solids. These compositions are of thewater-in-oil emulsion type. This means that the aqueous phase, whichconstitutes the internal phase, is finely distributed in the oil phaseand the oil phase forms the external phase.

Oil-based drilling fluids contain a base oil, which forms the externalphase, an aqueous solution containing a salt as the internal phase, andan emulsifier or emulsifier system, which acts on the boundary surfacebetween the internal and external phases. Other additives are used tostabilise and adjust the functional characteristics.

The advantage of oil-based drilling fluids lies in its excellentlubricating properties. These lubricating properties enable drilling tobe carried out with a considerable vertical offset, for example, as istypical of offshore or deep water drilling operations. In horizontal andalmost horizontal wellbores, the drill pipe lies on the lower side ofthe drill hole, which results in high torques when drilling and whendrawing the drill pipe. Under these conditions, the risk of a stuck pipeis greater when water-based drilling fluids are used. In contrast,oil-based drilling fluids form thin, flat filter cakes on the walls ofthe drilled hole and also have better characteristics than water-baseddrilling fluids with regard to the swelling of chalks that are usuallypresent in the formation rock.

Besides their lubricating properties, important functionalcharacteristics of oil-based drilling fluids also include viscosity,density and filtrate control. Filtrate control is particularly importantin unconsolidated permeable formations. In such conditions, underhydrostatic pressure the drilled material forms a semi-permeable,fluid-impermeable layer (for example in the form of a filter cake) onthe walls of the drilled hole, thus reducing fluid loss, stabilising theformation pressure and reducing that risk that the walls in the drilledhole will collapse.

When conventional emulsifiers are used, it may be necessary to usesolvents and other surface-active additives in order to penetrate thefilter cake and alter the wettability of the filter cake particles.Water-wetted solids are essential for a subsequent acid wash, todissolve or disperse the particles of the filter cake, for example.

Amine-based emulsifiers for invert emulsion drilling fluids that can beconverted from an oil-in-water emulsion into a water-in-oil emulsion aredescribed in WO 98/05733.

The complexity and unpredictability of the external conditions and theinteractions of the fluid components both with each other and with theconditions during drilling mean that a drilling fluid must be capable ofsustaining considerable loads, which poses a challenge for developers.There is a constant need, and thus also undiminished interest throughoutthe industry in new drilling fluids that offer improved performance andat the same time improved ecological and economical acceptance.

SUMMARY OF THE INVENTION

The object of the invention is providing a composition comprising awater-in-oil emulsifier system for use in or as a water-in-oil drillingfluid, hereafter also referred to in short as a drilling fluid, a usethereof, and a process, as described in the independent claims. Use ofthe emulsifier composition for water-in-oil emulsion is also claimed.Preferred embodiments are described in the subordinate claims or hereinbelow.

Surprisingly, a water-in-oil emulsifier system for use in “emulsiondrilling fluids” was found. Drilling fluids based on the emulsifiersystem according to the invention are notable for their surprisinglygood stability and other advantageous functional characteristics. Inparticular, increased stability is observed in respect of influencessuch as varying water and salt content (salinity) as well as usabilityover a wide range of temperatures. The water-in-oil emulsifier system isalso suitable for other applications, such as emulsifying water or brinein heavy oils, lowering viscosity and improving flow properties of heavyoil fractions.

Important application areas for the drilling fluids are boreholes fordeveloping oil and gas fields, geothermal bores or water drill holes, oralso drilling geo-scientific bores or mining drill holes.

The drilling fluid according to the invention comprises an oily, alsoreferred to as the oil phase, an emulsifier system comprising at leasttwo emulsifiers, water, optionally in form of brine, thickening agentsand further additives.

An example of additives used in the composition according to theinvention are the additives for wetting, weighting agents to increaseweight or density, “fluid loss” additives to minimise fluid loss,additives for creating an alkalinity reserve, additives for filtrationcontrol and/or to control rheological properties.

When the individual components of the composition according to theinvention are mixed with each other, a salt-like compound is formed thatis stable in a pH range between 4 and 10, preferably 3 and 11.

The emulsifier system contained in the composition has the effect oflowering interfacial tension due to the positive and negative partialcharges in the molecule. The interfacial activity can be adjusted intargeted manner by suitable selection of the degree of alkoxylation ofthe components of the emulsifier system.

By mixing the components of the emulsifier system comprising thealkoxylated amine and the carboxylic acid compound the appropriate HLB(Hydrophilic-Lipophilic-Balance) values can be adjusted to yield stableinvertible water-in-oil emulsion drilling fluids.

Emulsifying properties may be further optimised by an optionaladditional variation of the length of the hydrophobic C-chain in theemulsifier components. In this way, it is possible, for example, toproduce micro-emulsions under conditions of optimal temperature andoptimal salinity. Special formulations of surfactants with water and oilform a micro-emulsion (Winsor type III). The occurrence of certainphases is determined by internal (composition) and external parameters(such as temperature and salinity). The Winsor III phase, also known asa three-phase micro-emulsion (wherein the actual micro-emulsion is themiddle phase, coexisting with water and an oil excess phase), is notablefor extremely low interfacial tensions (IFT). This state is thereforealso described as “optimal”, and the associated parameters are describedas “optimal salinity” and “optimal temperature”. The middle phase isusually of low viscosity. A lower viscosity is desirable fortransporting highly viscous heavy crude oils or extra heavy crude oilsin pipelines for example.

In this way, it is also possible to produce stable invert emulsiondrilling fluids with excellent functional characteristics for anextremely wide range of conditions. As a rule, the degree ofalkoxylation is adjusted according to the oil and the brineconcentration used, and subsequently adjusted further as necessarydepending on the specific drilling conditions.

According to the invention, for example, the same mode of action may beachieved with an alkoxylated dodecylamine in combination with an ethercarboxylic acid on an alkoxylated oleyl alcohol base as with analkoxylated oleyl amine paired with a dodecyl alcohol-based ethercarboxylic acid.

In this way, the emulsifier system according to the invention enablesvariation options in adjusting the desired emulsifier functions andadapting said functions to the required operating characteristics of aninvert emulsion drill flushing fluid.

DETAILED DESCRIPTION OF THE INVENTION

In the following, the emulsifier system, the water-in-oil compositionand their application will be described.

The composition comprises one or more amine compounds (A) which are oneor more alkoxylated primary and/or secondary amine compounds or mixturesthereof, and a carboxylic acid component (B). The components (A) and (B)form the emulsifier system.

Suitable alkoxylated amine compounds according to the invention formingcomponent (A) are surface-active substances derived from or based on,for example, butylamine, pentylamine, hexylamine, octylamine,nonylamine, decylamine, undecylamine, lauryl amine, tridecylamine,tetradecylamine, pentadecylamine, palmityl amine, stearyl amine,arachidyl amine, behenyl amine, lignoceryl amine as well as unsaturatedor branched amines with the same C number, for example oleyl amine,2-ethylhexyl amine or standard commercial or other mixtures such ascoconut oil amine or tallow oil amine. Alkoxylated dialkyl aminecompounds derived from or based on compounds containing said C-chainlengths and/or heterocyclic, nitrogen-containing compounds, such asimidazol and piperazine, are also suitable.

The starting amine compounds used for the preparation of the alkoxylatedamine compound forming component (A) are amines having at least one NHvalence, for example, primary and/or secondary amines. The conversion ofthe amine with alkoxides is achieved by addition with either one or moreethylene oxide, propylene oxide and/or butylene oxide, including blockand/or statistical distributions, wherein the average numerical value ofalkoxylene units is between 0.5 and 30, preferably between 1 and 10, andmost preferred greater 1 to 6. The term “alkoxylated amines” accordingto another embodiment includes alkanolamines or dialkanolamines or inother words alkoxylated amines with only one or only two alkoxoylategroup(s).

The alkoxylated compounds consist preferably of (quasi) statisticalmixtures for example even at a degree of alkoxylation of 0.5 (and above)there always exist compounds with a degree of alkoxylation of two andthree per molecule. In this case several different amine compoundswithin components (A) with differing degree of alkoxylation are present.

The degrees of alkoxylation given throughout this invention are averagevalues (number average).

The carboxylic acid compound forming component (B) of the emulsifiersystem is selected from one or more members of the group ofmonocarboxylic acids, polycarboxylic acids, polyalkylene glycolethercarboxylic acids of a monoalcohol and polyalkylene glycol ethercarboxylic acids of a polyol. Suitable carboxylic acid compounds are forexample the following carboxylic acids: lactic acid, citric acid, oxalicacid, butyric acid, valeric acid, caproic acid, heptanoic acid, caprylicacid, nonanoic acid, capric acid, undecanoic acid, lauric acid,tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid,stearic acid, behenic acid and the branched and unsaturated types havingthe same C-chain length, such as oleic acid. The monocarboxylic acidsand the polycarboxylic acids preferably contain 4 to 24, particularly 8to 18, carbon atoms and particularly preferred 12 to 18 carbon atoms,optionally a hydroxy group. In particular preferred are monocarboxylicacids.

Alcohol polyalkylene glycol ether carboxylic acids based on for examplebutanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol,undecanol, lauryl alcohol, tridecanol, tetradecanol, pentadecanol,hexadecanol, heptadecanol, octadecanol, behenyl alcohol and thecorresponding branched or unsaturated types having the same C-chain suchas oleyl alcohol or iso-octanol are also suitable. The listed alcoholsand polyalkylene glycols with different chain lengths form the basis ofthe polyalkylene glycol ether carboxylic acids (B) that are produced bypolyaddition with either ethylene oxide, propylene oxide or butyleneoxide or mixtures thereof including random or block structures followedby carboxymethylation for example with chloroacetic acid or sodiumchloroacetate, wherein the average numerical value of the alkylene oxideunits is between 0 and 30, preferably between 0.5 and 10, particularlybetween 1 and 8.

The emulsifier composition comprising component (A) and component (B)according to the invention should preferably be mixed equimolar relatedto the functional groups, wherein the average degree of alkoxylation ofall amine compounds and all carboxylic acid compounds forming the totalmixture should preferably be between 0.5 and 30, particularly between 1and 10 and most preferred greater 1 to 6. The alkoxy groups are eithersolely within the amine compounds or within both, the carboxylic acidcompounds and the amine compounds.

The emulsifier system according to the invention is preferably solubleat 25° C. in the oil.

Exemplary emulsifier combinations are listed in the experimentalsection, others include: amine-C18-glycol-(2EO)-ether/lactic acidmixture (MARLAZIN OL2/lactic acid),oleyl-imidazoline/oxo-alcohol-C9-(2EO-2PO)-ether carboxylic acid mixture(MARLOWET 5440/MARLOWET 4539), amine-C18-glycol-(7EO)/coconut oil acidmixture MARLAZIN T7/2/coconut oil acid) oroleyl-imidazoline/alcohol-C6-glycol-(3EO-3PO)-ether carboxylic acidmixture (MARLOWET 5440/MARLOWET 4556).

Appropriate combination of the emulsifier components (A) and (B)according to the invention enables oils of different compositions to beused. Examples of oils forming component (C) are aliphatic orcycloaliphatic hydrocarbons such as alphaolefins (LAO),polyalpha-olefins (PAO), internal olefins (IO), diesel, biodiesel,Fischer-Tropsch distillates, esters, particularly ethyl and/ormethyl-(C12 to C22) fatty acid esters, alcohols, ethers, acetals,(oligo)amides, (oligo)imides and/or (oligo)ketones, also triglyceridesor mixtures thereof.

The oil is composed in such manner that it is liquid at 25° C.,preferably at 0° C. and most preferably at −10° C. The drilling fluidresulting from the addition of the composition according to theinvention is stable in the pH-value range between 4 and 10, preferablybetween 3 and 11. This pH range describes stability limits. Above andbelow these limits, the emulsion breaks and allows targeted separationof the various components.

The invertible drilling fluid emulsion obtained from the above describedemulsifier system may be broken and inverted by alkalisation with strongcaustic solutions such as KOH or NaOH above pH values of 11 or alreadyat pH values of above 10. In this case, the anionic emulsifier componentis hydrophilised and in this state it has the properties of anoil-in-water emulsifier. An inversion may also be achieved by additionof strong acids, for example, such as HCl or H₂SO₄ below a pH value of3. In this case the amine will be protonised and forms a salt with thecorresponding anion of the added acid.

The conversion is enabled particularly advantageously by readjusting thepH value of cleaved invert drilling fluid emulsions in the pH valuerange between 4 to 10, preferably 3 and 11, in a homogeneousoil-in-water emulsion (flipping), so that they are able to be reused asdrilling fluid.

It is possible to reuse a large portion of the drilling fluid byintroducing and adjusting the requisite additives listed previously forsaid use. In practice, it results in financial savings and shorterreconditioning process steps, which presents significant advantagesespecially in offshore drilling operations.

The invertibility of the drilling fluids according to the inventionenables the penetration of the filter cake and the wetting of the filtercake particles to be reversed. Solids that can be wetted with water areessential for the subsequent acid wash, so that for example theparticles of the filter cake can be dissolved with acid or dispersed,and also makes it easier to carry out the steps necessary forregenerating the oil-charged drilling material and subsequent removal,for example cleaning oil-contaminated solid surfaces with water-basedrinsing aids.

The composition according to the invention further contains water,forming component (F). The aqueous phase of the drilling fluid maycontain for example weighting agents, fluid-loss additives, alkalireserves, viscosity regulators, water-soluble and insoluble salts andthe like.

The drilling fluid according to the invention may contain up to 70% byweight water, preferably 20 to 40% by weight, for example 30% by weightwater, particularly a salt-containing aqueous phase (brine) is usuallyused.

The emulsifier components are adjusted suitably and an appropriateconcentration is used within the limits of this invention. The drillingfluid according to the invention is capable to emulsify substantialquantities of water even electrolyte-rich water, such as e.g. CaCl₂solutions or brine. This property of the drilling fluid according to theinvention means that it may also be used to absorb water that settles inthe lower region of the drilled hole caused by the ingress of water,without interrupting the drilling operation.

Other additives may also used besides the emulsifier or emulsifiersystem, including for example wetting agents, weighting agents toincrease weight or density, “fluid loss” additives to minimise fluidloss, additives for creating an alkalinity reserve, for filtrationcontrol and/or to control rheological properties.

Lime or other alkaline substances may be added to oil-based drillingfluids in order to create an alkalinity reserve. The alkalinity reserveserves to maintain the viscosity and stability of the drilling fluidwhen the drilling fluid is exposed to variable external influences. Thisis particularly important in areas where acidic gases such as CO₂ or H₂Sare encountered during drilling. In the absence of an alkalinityreserve, acidic gases can lower the pH value of the drilling fluid andthus weaken the emulsion stability and undesirably change the viscosityof conventional drilling fluids. Repair or removal of the drilling fluidis expensive and therefore undesirable.

The drilling fluid according to the invention may contain thickeningagents such as clays consisting of bentonite, hectorite, attapulgiteand/or mixtures thereof, particularly such mixtures as have beenrendered organophilic by surface treatment. Surface treatment may becarried out with quaternary ammonia compounds, for example, so that theclays are rendered hydrophobic. The clays are used in a concentrationfrom 1 to 10% by weight. The polar character of the emulsifyingcomponent according to the invention may reduce the quantity ofthickening agent required depending on the type of the thickening agentin question.

Additives selected from the group including alkaline and alkaline earthhalides, sulphates, carbonates, hydrogencarbonates, also hydroxides andiron oxides, create what is known as an alkalinity reserve.

For example, in “acid gas drilling” acid gases such as CO₂ and H₂S maybe absorbed. The drilling fluid according to the invention is stable inthe pH value range from 4 to 10, preferably from 4 to 10, and thereforeprovides a substantial alkalinity reserve in the upper pH value range(10 to 10.5). The density of the drilling fluid may also be modified viathe salt concentration in the water phase.

Emulsifier components (A) and (B) are preferably used in a molar ratiorelated to the respective numbers of the functional groups (amine orcarboxylic acid) from 1:1.5 to 0.5 to 1, particularly 1:1.2 to 0.8 to 1.

The pH value of the drilling fluid according to the invention may beadjusted to pH values above 4. Preferably from 8 to 10.0 or 10 to 10.5by appropriate mixing of the emulsifying components (A) and (B)according to the invention, such that the drilling fluid already has itsown alkali reserve.

At the same time, the emulsifying components (A) and (B) according tothe invention have a corrosion inhibiting effect for metal surfaces andreduce frictional resistances, thus functioning as lubricants.

The invention further relates to a composition (the drilling fluid)comprising at least components (A) to (F):

-   -   (A) one or more primary, secondary or tertiary alkoxylated amine        compounds and    -   (B) one or more carboxylic acid compounds selected from one or        more members of the group of monocarboxylic acids,        polycarboxylic acids, polyalkylene glycol ether carboxylic acids        of a monoalcohol and poly-alkylene glycol ether carboxylic acids        of a polyol,    -   (C) an oil that is fluid at 25° C., and    -   (D) one or more thickening agents for thickening the oil or the        oil phase, selected from the group including clays, polymers,        alumina and silica, and    -   (E) one or more additives selected from the group including        alkaline and earth alkaline halides, sulphates, carbonates,        hydrogencarbonates, also hydroxides and iron oxides, and    -   (F) water        and optionally wetting agents, weighting agents to increase        weight or density, “fluid loss” additives to minimise fluid loss        and a method for drilling a drill hole using above        composition/drilling fluid comprising the step of introducing        the drilling fluid into the drilled hole during the drilling        operation.

In this context, the method may further comprise steps according towhich the drilling fluid including the drilled material (cuttings) isextracted, the drilled material is separated from the drilling fluid,for example by sieving or centrifuging, and the cleaned drilling fluidis reintroduced into the drilled hole, optionally after the addition ofcomponents such as those described in the preceding, which have beendepleted in the drilling fluid during the drilling operation.

The separated drilled material may be treated with an alkali or an acidsolution to break the residual drilling fluid in the form of awater-in-oil emulsion by adjusting a pH value lower than 3 or higherthan 10, particularly higher than 11, and thus obtain an oil-in-wateremulsion as a flushing fluid and a fluid for removing the oil from thedrilled material, in order to obtain a drilled material even furtherdepleted of the oil.

Another use of the emulsifier system according to this invention is theimprovement of the cold flow properties of heavy crude oils and extraheavy crude oils. Heavy crude oils are defined as any liquid petroleumwith an API gravity less than 20°. Extra heavy oil is defined with APIgravity below 10.0° API. In this use the heavy or extra heavy crude oilbecomes the oil (C) or the oil phase of the composition according to theinvention. API is measured according to ASTM D287.

EXPERIMENTAL SECTION

Various compositions were prepared using the following components.

25% CaCl₂ solution MISwaco, HoustonBarium sulphate M-I BAR, MISwaco, Houston

Lime Austin White Lime Company, Austin Mineral oil Gravex 915, Shell

Wetting agent FM WA II, Fluid Management Ltd. HoustonPolymer thickening agent HRP, MI Swaco, Houston

Quartz Milwhite Inc. Clay FM VIS LS, Fluids Management, Houston Example1

A diesel-based drilling fluid was prepared at room temperature from thecomponents listed below, combined in the order described, having beenhomogenised beforehand using a Hamilton Beach overhead mixer on fullpower for about 40 minutes and being homogenised within 5 minutesafterwards in a Silverson L4RT mixer at 3500 rpm. The mixture wasevaluated visually taking into account the precipitation of organic,aqueous and inorganic phases.

Product Unit 1.1 1.2 1.3 1.4 Diesel % by wt. 28.0 28.0 28.0 28.0 Clay %by wt. 1.0 1.0 1.0 1.0 Polymer thickening agent % by wt. 0.2 0.2 0.2 0.2Lime % by wt. 0.7 0.7 0.7 0.7 Emulsifier 1: Oxo-C13-alcohol glycol- % bywt. 1.8 — — — (3EO)-ether (MARLIPAL O13/30) Emulsifier 2:Amine-C18-glycol- % by wt. — 1.8 — — (2EO)-ether/alcohol C1214-glycol-(3EO)-ether carboxylic acid mixture (MARLAIN OL2/MARLOWET 4541)Emulsifier 3: Amine-C18- % by wt. — — 1.8 — glycol-(2EO)-ether (MARLAZINOL 2) Emulsifier 4: C1214-glycol- % by wt. — — — 1.8 (3EO)-ethercarboxylic acid (MARLOWET 4541) Wetting agent % by wt. 0.003 0.003 0.0030.003 25% CaCl2 solution % by wt. 18.3 18.3 18.3 18.3 Barium sulphate %by wt. 45.0 45.0 45.0 45.0 Quartz % by wt. 5.0 5.0 5.0 5.0 StabilityHrs. <2/<1 >16/>16 <1/<1 <4/<2 Temperature ° C. 20/70 20/70 20/70 20/70(EO = monomer unit ethylene oxide, PO = monomer unit propylene oxide)

Example 1 shows that selection of an emulsifier system consisting ofamine-C18-glycol-(2EO)-ether/alcohol C1214-glycol-(3EO)-ether carboxylicacid enabled stability to be maintained for >16 hours both at roomtemperature and at 70° C.

This could not be achieved using the single components described asEmulsifier 3 and Emulsifier 4, also not with Emulsifier 1.

Example 2

A rapeseed methyl ester-based drilling fluid was prepared as inexample 1. Selection of an emulsifier system consisting ofamine-C18-glycol-(2EO)-ether/alcohol C1214-glycol-(5EO)-ether carboxylicacid enabled the stability required for this application to bemaintained for >16 hours both at room temperature and at 70° C.

Product Unit 2.1 2.2 Rapeseed methylester % by wt. 28.0 28.0 Clay % bywt. 1.0 1.0 Polymer thickening agent % by wt. 0.2 0.2 Lime % by wt. 0.70.7 Emulsifier 1: Oxo-C13-alcohol-glycol- % by wt. 1.8 — (5EO)-ether(MARLIPAL O13/50) Emulsifier 2: Amine-C18-glycol- % by wt. — 1.8(2EO)-ether/alcohol C1214-glycol- (5EO)-ether carboxylic acid mixture(MARLAZIN OL 2/MARLOWET 1072) Wetting agent % by wt. 0.003 0.003 25%CaCl₂ solution % by wt. 18.3 18.3 Barium sulphate % by wt. 45.0 45.0Quartz % by wt. 5.0 5.0 Stability Hrs. <1/<1 >16/>16 Temperature ° C.20/70 20/70

Example 3

A rapeseed methyl ester-based drilling fluid was prepared as inexample 1. Selection of an emulsifier system consisting ofamine-C18-glycol-(2EO)/lactic acid enabled the stability required forthis application to be maintained for >16 hours both at room temperatureand at 70° C.

Product Unit 3.1 3.2 Mineral oil % by wt. 28.0 28.0 Clay % by wt. 1.01.0 Polymer thickening agent % by wt. 0.2 0.2 Lime % by wt. 0.7 0.7Emulsifier 1: Nonyl phenol-glycol- % by wt. 1.8 — (3EO)-ether (MARLOPHENNP3) Emulsifier 3: Amine-C18-glycol- % by wt. — 1.8 (2EO)/lactic acidmixture (MARLAZIN OL2/lactic acid) Wetting agent % by wt. 0.003 0.00325% CaCl₂ solution % by wt. 18.3 18.3 Barium sulphate % by wt. 45.0 45.0Quartz % by wt. 5.0 5.0 Stability Hrs. <3/<1 >16/>16 Temperature ° C.20/70 20/70

Example 4

A drilling fluid based on paraffin oil (technical, low-aromatic standardoil) was prepared as in example 1. Selection of an emulsifier systemconsisting ofamine-C12-glycol-(2EO)-ether/alcohol-C1618-glycol-(2EO-2PO)-ethercarboxylic acid enabled the stability required for this application tobe maintained for >16 hours both at room temperature and at 70° C.

Product Unit 4.1 4.2 Paraffin oil % by wt. 28.0 28.0 Clay % by wt. 1.01.0 Polymer thickening agent % by wt. 0.2 0.2 Lime % by wt. 0.7 0.7Emulsifier 1: C18-alcohol-glycol- % by wt. 1.8 — (5EO)-ether (MARLOWET5001) Emulsifier 2: Amine-C12-glycol- % by wt. — 1.8 (2EO)-ether/AlcoholC1618-glycol- (2EO-2PO)-ether carboxylic acid mixture (Trialproduct/MARLOWET 4560 Wetting agent % by wt. 0.003 0.003 25% CaCl2solution % by wt. 18.3 18.3 Barium sulphate % by wt. 45.0 45.0 Quartz %by wt. 5.0 5.0 Stability Hrs. <3/<1 >16/>16 Temperature ° C. 20/70 20/70

Example 5

In order to study the improvement of cold flow properties of heavy crudeoils and extra heavy crude oils achieved by adding the emulsifier systemand water the following model liquid consisting of:

-   -   MERKUR WOP 240 (Mineral oil with 30% naphthenic bounded CW and        70% paraffin thereof are 80% iso paraffin and 20% n-paraffins        (C25 to C42),    -   PARAFOL 22-95 n-Docosan (min 95%),    -   PARAFOL 18-97 n-Octadecan (min. 97%),    -   SASOLWAX 3971 iso paraffin (C24 to C80), microcrystalline wax        was used having the following composition:

Model Liquid [% by weight] MERKUR WOP 240 60 PARAFOL 22-95 10 PARAFOL18-97 5 SASOLWAX 3971 25

Water in Oil—Emulsion Composition:

Emulsion [% by weight] C12-C14 2 EO Ether carboxylic acid + 0.75 Tallowfatty amine 1EO Model Liquid 94.25 Water comprising 10 weight % CaCl₂.5.0

The emulsifier is added to the oil phase. Thereafter the water is addedwhile stirring gently achieving spontaneously an emulsion showing thefollowing viscosities at different temperatures.

Temperature Emulsion Model Liquid [° C.] [mPas] [mPas] 30 4300 5550 401700 2650 50 900 1400 60 350 450

Viscosity is measured using a Haake Mars 2 cone plate system (35/2°) ata shear rate of 10/s

1. A composition comprising: (A) at least one of primary, secondary,tertiary alkoxylated amine compounds, or mixture thereof and (B) atleast one of carboxylic acid compounds selected from at least one ofpolyalkene glycol ether carboxylic acids of a monoalcohol, poly-alkyleneglycol ether carboxylic acids of a polyol, or mixtures thereof (C) anoil that is liquid at least at 25° C., and (F) water, wherein thecomposition further comprises salts dissolved in the water (F) in aconcentration of greater than 1% by wt. an the composition is awater-in-oil-emulsion wherein the oil (C) forms the continuous phase andthe water (F) forms the dispersed phase.
 2. The composition according toclaim 1, wherein the polyalkylene glycol ether carboxylic acids of amonoalcohol and/or a polyol have the general formulaR³—[—O—(Z)_(p)-E]_(y) wherein R³ stands for a hydrocarbon radical with 1to 24 hydrocarbon atoms, Z stands for alkoxylate groups —CH2-CHR2-O— or—CHR2-CH2-O— which may or may not be different for each p, R² stands forH, a methyl group or an ethyl group, which may or may not be differentfor each p, E stands for —CH₂—COOH, p stands for average numericalvalues from greater than 0 to 15 and y is 1 in the case of amonoalcohol, and 2, 3, 4, 5 or 6 in the case of a polyol.
 3. Thecomposition according to claim 1, wherein the amine compounds have thefollowing general formulaR¹—N(—X_(n)H)(—X_(m)H) or (R¹—)(R4-)N(—X_(n)H) in which R¹, R⁴ eachstand for a hydrocarbon radical with 4 to 24 hydrocarbon atoms, X standsfor CH₂—CHR²—O— or —CHR²—CH₂—O—, and may or may not be different foreach m and n, R² stands for H, a methyl group or an ethyl group and mayor may not be different for each m and n, n and m independently of oneanother stand for average numerical values from greater than 0 to 30,and independently thereof the sum of n plus m is equal to a value fromgreater than 0.5 to
 30. 4. The composition according to claim 3, whereinfor R¹—N(—X_(n)H)(—X_(m)H) n+m+p is between 2 and 8 and for(R¹—)(R⁴—)N(—X_(n)H) n+p is between 2 and
 8. 5. The compositionaccording to claim 1, wherein the amine compound is an alkoxylatedimidazol, alkoxylated piperazine, or mixtures thereof.
 6. Thecomposition according to claim 1, wherein the oil (C) has a flashpointhigher than 60° C. and which is measured at temperatures of higher than60° C. up to 70° C. according to DIN 51755 and at temperatures higherthan 70° C. according to EN ISO
 2719. 7. The composition according toclaim 1, wherein the oil (C) comprises hydrocarbons, esters, alcohols ormixtures thereof.
 8. The composition according to claim 1, wherein thecomposition further comprises salts dissolved in the water (F) in aconcentration greater than 5% by wt.
 9. The composition according toclaim 1, wherein the composition further comprises (D) at least onethickening agent for thickening the oil, and (E) at least one additiveselected from the group consisting of alkaline and earth alkalinehalides, sulphates, carbonates, hydrogencarbonates, hydroxides, ironoxides, and mixtures thereof.
 10. The composition according to claim 9wherein (D) the thickening agent is a clay selected from bentonite,hectorite, attapulgite and mixtures thereof.
 11. The compositionaccording to claim 9, wherein the additive (E) is calcium carbonate,barium sulphate, iron-III-oxide or mixtures thereof.
 12. The compositionaccording to claim 1, wherein the composition has a pH value from 3 to11.
 13. The composition according to claim 9, wherein the compositioncomprises independently of each other 0.05 to 10% by wt. amine compound(A) and carboxylic acid compound (B), (C) 5% by wt. to 50% by wt. theoil, (D) 0.05% by wt. to 5% by wt. the thickening agent, (E) 1% by wt.to 60% by wt. the additive, (F) 2% by wt. to 50% by wt. water.
 14. Thecomposition according to claim 9, comprising the amine compound (A) andthe carboxylic acid compound (B) in molar ration from 1:1.5 to 0.5 to 1,each related to the number of amine and carboxylic acid functionalgroups in (A) and (B).
 15. A method for drilling an earth borehole,comprising the steps of introducing a drilling fluid into the earthborehole during the drilling operation, said drilling fluid comprising(A) at least one of the primary, secondary, tertiary, alkoxylated aminecompounds or mixtures thereof, (B) at least one of carboxylic acidcompounds selected from poly-alkylene glycol ether carboxylic acids of amonoalcohol, poly-alkylene glycol ether carboxylic acids of a polyol, ormixtures thereof, (C) an oil that is liquid at least at 25° C., and (F)water.
 16. The method according to claim 15, further including the stepof extracting the drilling fluid including drilled material, separatingthe drilled material out of the drilling fluid, and returning thedrilling fluid to the earth borehole minus the separated drilledmaterial.
 17. The method according to claim 15 further including thestep of extracting the drilling fluid including drilled material,bringing at least a portion of the drilling fluid into contact with oneof a base or an acid to break the water-in-oil-emulsion by setting a pHvalue of lower than 3 or higher than 11, respectively to obtain aninverted emulsion being an oil-in-water emulsion.
 18. The methodaccording to claim 17 including the step of exposing the invertedemulsion being an oil-in-water emulsion to one of a base or acid thussetting a pH value from 3 to 11, respectively to obtain a water-in-oilemulsion.
 19. The method according to claim 16, further including thestep of bringing the drilled material into contact with one of a base oracid to break the water-in-oil emulsion by setting a pH value of lowerthan 3 or higher than 11, respectively, wherein an oil-in-water emulsionflushing fluid and a drilled material minus the oil are obtained. 20.The method of claim 15, wherein said earth borehole comprises one of anoil and gas well, a geothermal well or a water well.
 21. (canceled) 22.A method of improving flow of heavy hydrocarbons comprising introducinga composition comprising: (A) one or more primary, secondary or tertiaryalkoxylated amine compounds and (B) one or more carboxylic acidcompounds selected from one or more members of the group of polyalkyleneglycol ether carboxylic acids of a monoalcohol and poly-alkylene glycolether carboxylic acids of a polyol, (F) water, wherein the compositionfurther comprises salts dissolved in the water (F) in a concentration ofgreater than 1% by wt. and the composition is a water-in-oil-emulsionwherein the oil (C) forms the continuous phase and the water (F) formsthe dispersed phase, into heavy crude oils or extra heavy crude oils toform water-in-oil emulsions with reduced viscosity.
 23. A method offorming a water-in-oil emulsion comprising: introducing a compositioncomprising: (A) one or more primary, secondary, or tertiary alkoxylatedamine compounds and (B) one or more carboxylic acid compounds selectedfrom one or more members of the group of polyalkylene glycol ethercarboxylic acids of a monoalcohol and poly-alkylene glycol ethercarboxylic acids of a polyol, into a mixture of water and oil.
 24. Thecomposition according to claim 3, wherein R¹ and R⁴ form at least onering with a total of 4 to 24 hydrocarbon atoms.
 25. The compositionaccording to claim 6, wherein said flashpoint according to DIN 51755 isgreater than 70° C.
 26. The composition according to claim 7, whereinsaid hydrocarbons are aliphatic or cycloaliphatic and the esters areethyl and/or methyl (C12 to C22) fatty acid esters.
 27. The compositionaccording to claim 8, wherein said salts are in a concentration greaterthan 15% by wt.
 28. The composition according to claim 8, wherein saidsalts are in a concentration greater than 20% by wt.
 29. The compositionaccording to claim 9, wherein said thickening agent is selected from thegroup consisting of clays, polymers, alumina, silica, and mixturesthereof.
 30. The composition according to claim 10, wherein thethickening agent is an organically modified clay.
 31. The compositionaccording to claim 10, wherein said clay is organically modified with afatty amine.
 32. The composition according to claim 11, wherein saidadditive may be in the form of minerals.
 33. The composition accordingto claim 12, wherein said pH is from 4 to
 10. 34. The compositionaccording to claim 13, wherein the composition comprises 0.1% by wt. to5% by wt. (A) and (B).
 35. The composition according to claim 13,wherein (C) is present in an amount of from 10% by wt. to 20% by wt. 36.The composition according to claim 13, wherein (D) is present in anamount of from 0.5% by wt. to 3% by wt.
 37. The composition according toclaim 13, wherein (E) is present in an amount of from 30% by wt. to 50%by wt.
 38. The composition according to claim 13, wherein (F) is presentin an amount of from 2% by wt. to 40% by wt.
 39. The compositionaccording to claim 13, wherein (F) is present in an amount of from 2% bywt. to 30% by wt.
 40. The composition according to claim 14, wherein aidmolar ration is from 1:1.2 to 0.8 to
 1. 41. The method according toclaim 15, wherein said drilling fluid further comprises: (D) at leastone thickening agent for thickening the oil, (E) at least one additiveselected from the group consisting of alkaline and earth alkalinehalides, sulphates, carbonates, hydrogencarbonates, hydroxides, ironoxides, and mixtures thereof.
 42. The method according to claim 15,wherein said drilling fluid further comprises: (E) at least one additiveselected from the group consisting of alkaline and earth alkalinehalides, sulphates, carbonates, hydrogencarbonates, hydroxides, ironoxides, and mixtures thereof.
 43. The method according to claim 42,wherein said drilling fluid further comprises: (D) at least onethickening agent for thickening the oil.
 44. The method according toclaim 16, wherein the drilling fluid minus the separated drilledmaterial is returned to the earth borehole after the addition of atleast one of components (A) to (F).
 45. The method according to claim17, wherein drilled material is removed prior to bringing said drillingfluid into contact with said base or acid.